Rotor brake



May 7, 1957 F. E. BACHMAN x-:rAL 2,791,294

' RoToRV BRAKE Filed Feb. 29. 1952 4 shams-Sheet 1 j-BO nehme feimalcflSI/In lviay 7, 1957 F. E. BACHMAN ETAL. 2,791,294

ROTOR BRAKE 4 Sheets-Sheet 2 Filed Feb. *129, 1952 May 7, 1957 FiledFeb. 29, 1952 F. E. BACHMAN ETAL 2,791,294

ROTOR BRAKE 4 Sheets-Sheet 3 May 7, 1957 2,791,294

F. E. BACHMAN ET Al.

RoToR BRAKE Filed Feb. 29, i952 4 sheets-sheet 4 'l lll/lll UnitedStates Patent O ROTOR BRAKE Fred E. Bachman, Granite City, Ill., Gordon0. Buc-hholz, St. Louis, Mo., and Mehmet Kemal Coskun, Granite City,Ill., assignors to American Steel Foundries, Chicago, lll., acorporation of New Jersey Application February 29, 1952, Serial No.274,196

6 Claims. (Cl. ISS-59) This invention relates to brake rigging forrailway cars and is more particularly concerned with the provision of adisk type brake arrangement in which a disk or rotor secured to a wheeland axle assembly is frictionally engaged between a pair of stators orbrake shoe forming part of and actuated by a brake mechanism supportedupon a truck frame.

Briefly, the present invention contemplates the provision of a diskbrake structure in which the brake shoe actuating mechanism is providedwith spaced coaxial trunnions engaged in cylindrical resilient bushingsmounted in support brackets bolted or otherwise secured to a truck frametransom. To engage the brake shoe actuating mechanism against rotationalmovement about the axis of the trunnions, a torque arm is secured at oneof its ends to a trunnion and has its other end engaged in a slotprovided in the adjacent support bracket, the slot being formed topermit vertical movement of the actuating mechanism and torque armrelative to the bracket responsive to engagement and disengagement ofthe brake shoes with the disk or rotor. By forming the bushings ofresilient material such as rubber, the actuating mechanism is supportedfor limited axial movement relative to the truck frame responsive toaxial movement of the wheel and axle assembly during application of thebrake shoes to the opposite sides of the rotor.

In railway truck structures, the truck frame is commonly springsupported from an equalizer arrangement seated upon the journal ends ofthe wheel and axle assemblies and the truck frame is movable verticallyrelative to the wheel and axle assemblies. It will thus be understoodthat some provision must be made for maintaining the brake shoes inproper alignment with the rotor throughout movement of the truck framerelative to the wheel and axle assemblies. It is therefore anotherobject of this invention to provide a brake arrangement in which thebrake shoes at all times are maintained in proper braking positionrelative to the rotor.

This invention embodies other novel features, details of constructionand arrangement of parts which are hereinafter set forth in thespecication and claims and illustrated in the accompanying drawings,wherein:

Figure l is a top plan view of a brake structure em bodying features ofthe present invention, the structure being shown as applied at onecorner of a conventional four wheel railway car truck;

Figure 2 is a side elevational view of same;

Figure 3 is a sectional View taken along the line 3 3 of Figure 2;

' Figure 4 is a detail sectional view taken along the line 4 4 of Figure3;

A Figure 5 is a detail plan view showing a brake head and shoe assembly;

Figure 6 is a side elevational view of same;

i Figure 7 is an end elevational view illustrating a modied form of theinvention;

the line 8 3 of Figure 7, and Y A v ICC Figure 9 is a detail sectionalview taken along the line 9 9 of Figure 8.

Referring now to the drawings for a better understanding of thisinvention and more particularly to Figures l to 6 therein, the brakestructure is shown as applied to a conventional four wheel railway cartruck comprising a truck frame 2 having integral side rails 4 4, endrails 6 6, and spaced intermediate transoms 8 8 between which may besupported for lateral movement a bolster on which the car body may bemounted in the usual manner.

The truck frame 2 is resiliently supported upon equalizers 10 10extending below the side rails and provided with spring seats 12 toengage the lower ends of compression springs 14, the upper ends of thesprings being engaged against spring seats 16 provided on the undersideof the side rails. The ends of the equalizers are mounted inconventional manner upon journal boxes (not shown) guided for verticalmovement between pedestal legs 18 18 provided on the ends of the siderails, each pair of journal boxes engaging the journal ends of a wheeland axle assembly 20 embodying an axle 22 and a pair of wheels 24 24.

A disk or rotor 26 is bolted to the hub 28 of each wheel 24 forengagement between a pair of brake shoes 3tl 30 which, as illustrated inFigures 2 and 5, are preferably of crescent shape to insure that theentire friction face of each shoe shall be in position to frictionallyengage the rotor when the latter moves vertically relative to the shoesduring normal operation of the truck.

The brake structure is shown as comprising a housing 32 formed withcoaxial trunnions 34 3S resiliently mounted in bearing brackets 36 37,respectively, by means of cylindrical resilient bushings 38 38a. Eachbushing preferably comprises a tubular length of resilient material 40such as natural or synthetic rubber bonded to and between an outer metalsleeve 42 and an inner metal sleeve 44. The upper end of the bracket 36is disposed between and secured to a pair of spaced webs 46 46 by meansof bolts 48, the webs being preferably formed integral with the truckframe 2` The upper end of the bearing bracket 37 is secured to amounting bracket 50 by means of bolts 52, the mounting bracket beingpreferably welded at 54 to the adjacent transom 8.

A torque arm 56 is welded at 58 to the trunnion 34 and extends upwardlyalong the inboard side of the bearing bracket 35 for engagementtherewith to prevent rotational movement of the housing 32 responsive tofrictional engagement of the brake shoes 3t 30 with the sides of therotor 26. The upper end of the torque arm 56 is formed with a laterallyprojecting lug 60 which is disposed within a slot 62 formed in thebearing bracket, the slot having its long axis disposed vertically topermit limited relative vertical movement of the torque arm and bearingbracket,

It will be noted that the torque arm 56 engages the inboard edge of theinner metal sleeve 44 and that an annular flange 64 engages the outboardedge of the outer metallic sleeve 42 to thus engage the resilientbushing 38 against axial displacement. The resilient bushing 38a issecured against axial displacement from the trunnion 35 by means of anannular flange 66 formed on the inboard side of the bearing bracket 50to engage the adjacent edge of the outer sleeve 42, and by means of acollar 68 welded on the trunnion 35 to engage the adjacent edge of theinner sleeve 44.

A pair of brake levers 70 7l are pivotally mounted intermediate theirends at 72 on the housing 32, the inner ends of the levers being engagedand moved apart by any suitable power means such as a double actingcartridge type cylinder 73 which may be of the type disclosed in thepatent to TackV No. 2,355,122 in which'.

3. fluid under pressure is introduced into the cylinder to actuate apair of pistons 75-75. A brake head 74 is pivotally connected to theouter end of each lever 70 byf means of` a. pivot pin 76. and is adaptedtoV have? a brake shoe 30 secured thereto by rivets-.78'.

As illustrated in Figures and 6 in the drawings, the

brake shoe is shown as comprising a plurality of blocks of suitablefriction material 80 bonded 'to a relatively thin sheet metal backingplate 82` The backing plate 82 and brake head 74 are of similar crescentshape with their outer arcuate edges having a radius of curvaturesmaller` than the radius of the rotor 26, as illustrated in Figure 2, tomaintain the entireV friction face ofthe brake shoe in frictionalengagement with the rotor during,`

vertical movement of the rotor relativeto the1truck frame. Each brakehead isprovided with a guide means to align the brake shoes with thefriction faces on oppositesides of 'the rotor, said means comprising aguide plate 84,l secured to each head by means of its associated pivotpin 76 and including a vertical web 86 in ush abutting engagementagainstY the head. Each guide plate 84 is provided with an invertedV-shaped-portion 88 to re ceive a guide tongue 90 secured on. thehousing 32. The brake head, guide means is shown and described withgreater particularity in a copending application filed February 17,1951, Serial No. 211,515, inthe name of William J. Casey, now Patent No.2,690,237.

Figures 7, 8 and 9 illustrate a modified form of the invention in whichthe journalv 34 of the housing 32' is resiliently mounted in the lowerend of a bearing bracket 92 secured between a pair of spaced webs 94--94on the transom 8 by means of bolts 96. A torque arm 98 is secured on thetrunnion 34 and projects upwardly therefrom for engagement with anadjustment bolt 100 journaled in the webs 94-94. A cylindrical camV 102is eccentrically mounted on the bolt 100and secured against rotationalmovement relative thereto by means of a dowel or rivety 104, and thetorque arm 98 is formed with a slot 106 to slidably receive the camduring vertical movement of the torque arm relative to the truck frame.By rotating the adjustment bolt 100it will be noted that the brake shoesare raised or lowered, as desired, relative to the axis of the rotor. Tolock the adjustment bolt 160 in fixed position, a pair of apertured earsS-108 are formed on the `torque arm to straddle the head 110 of thebolt, the head being formed with a. plurality of angularly spacedopenings 112 to receive a cotter pin 114 having its ends engaged in theapertured ears.

VAn off-wheel brake structure of the type thus shown and described isadapted to be resiliently supported on the transom of a railway cartruck frame adjacent each wheel of the truck to decelerate a car, and itwill be noted that the brake shoe actuating mechanism is formed asacomplete unit adapted to be mounted on or removed from the framewithout difficulty or the use of special tools.

By providing the brake structure with brake heads and shoes of crescentshape, it will be noted that the structure may be greatly simplified byproviding a torque arm. on the brake shoe actuating mechanism tofengageone of the mounting brackets for relative vertical movement. Duringvertical movement of the wheel and axle assembly relative to the truckframe, it will be noted that the crescent-shaped brake shoes will bepositioned at all times in full face engagement with the brake disk. Inother` types of rotor brake structures, it` has been necessary toprovide means to rotate the brake shoe actuating mechanism responsive tovertical movement of the wheel and axle assembly relative to the truck`frame.

We claim:

l. In a railway car truck, a wheel and axle assembly,

atruck frame spring supported therefrom, said frameV comprising atransom member integrally formed therewith and extending transverselythereof adjacent and approximately parallel to said assembly, a brakedisk secured to and rotatablewithsaid assembly, spaced pairs of mountingwebs integrally formed with the transom, an outboard bracket fixedlysecured to the outboard pair of said mounting webs, said outboardbracket depending from said webs and presenting on the lower end thereofa cylindrical opening, an inboard bracket secured to the inboard pair ofsaid webszandzdepending therefrom, said inboard bracket presenting atthe lower end thereof a cylindrical opening axially aligned with saidfirst mentioned cylindrical opening, a braking device comprising ahousing interposed between said brackets, cylindrical trunnions onopposite sides. of said housing extending into the openings intheinboardcandy outboard"L brackets respectively, resilientfbushingspositioned in said openings in the inboard and'outward brackets andinterposed between the related trunnion and the related bracket, each ofsaid bushings being secured to the related bracket and the relatedtrunnion, a torque arm lixedly secured to. one off said trunnions,isaidtorque arm extending upwardly from said one 'trunnion adjacent one ofvthe brackets,- and a pin' and slot connection between said torquearm'andthe related one bracket, said connection being spaced from theV relatedtrunnion a greater distance, thanitsnspacing,V from the connectionbetween the related bracket and related mounting webs, the slot of saidpin.` andslot connection being.y elongated and having itstlong axisdirectedsubstantially vertically and its short axis directed:substantially horizontally whereby vertical movement of said housing, islimitedly accommodated and` rotational movement of' said housing on saidtrun-v nionsispositively restrained.

2. In'a railway car truck, a wheel and axle assembly, a truck frameflexibly supported therefrom, a transom forming-part of the-frame' andextendingl generally transversely of: the truck adjacent said assembly,and brake means operative to decelerate'the truck, said brake meanscomprising `a disk secured to and rotatable with said assembly,atmovable shoe carryingbrake-package adjacent the disk, and' means tosupport the package from the transom member, said last mentioned meanscomprising trunnions extending from opposite sides of the package,spaced bracket members connected to and'depending from the transom andeachfhaving on the lower end thereof apertures respectively receivingthe trunnions, resilient means interconnecting each trunnion andrelatedybracket member, and altorque arm member secured to one of the trunnions.and extending upwardly therefrom, and a connection between the torquearm and one of the bracket members at a point immediately adjacent theconnection between said one bracket member andthe related transom andsubstantially spaced from the connection between the torque arm and therelated trunnion.

3: Ina railway car truck, a wheeland'axle assembly, a trucky framespring supported from the assembly and comprising a'transom extendingtransversely of the frame ad# jacent the assembly, .brake means todecelerate the truck comprising-a1 disk rotatablewth the'assembly, aspring package positioned adjacent the disk and having movable frictionshoes operative to engage opposite sides of the disk-,means to supportsaid package from thetframe comprising coaxial trunnions. extending fromopposite sides of the package, spaced brackets members havingaperturesat thev lower ends thereof receiving the trunnions`respectively, said bracket membersv extending upwardly and having theirupper ends secured to thextransom, a torque. arm member securedto one of`said trunnions, said torque arm member extending generallyupwardlyifrom its related trunnion, .anda pin and. sloti connectionbetween one of the bracket members and the torque. arm member,saidconnection being located immediately adjacent the point ofconnection between said one bracket' and the transom and'relativelysubstantiallyspaced from thepoint of connection between the; torquearmmember and the related trunnion, said pin andsloticonnection comprisinga slotinone ofthe members` and'lay pin secured to the other of saidmembers, saidslotl having its long axis extending vertically, wherebyrelatively substantial movement of the brake package in a verticaldirection is accommodated, said slot having its short axis extendingsubstantially horizontally whereby rotational movement of the brakepackage on its trunnions is positively restrained.

4 In a railway car truck according to claim 3, wherein said slot islocated on the related bracket member.

5. In a railway car truck, a wheel and axle assembly, a truck frameresiliently supported from the assembly and including a transom memberextending transversely of the truck adjacent said assembly, and brakemeans operative to decelerate the truck, said brake means comprisingrotatable friction surfaces on said assembly, friction means engageablewith said surfaces, a movable brake package carrying said friction meansand positioned adjacent said friction surfaces, land means to supportthe package from the transom member, said last mentioned means includingtrunnions extending from opposite sides of the package, a pair of spacedbracket members connected to and depending from the transom member andhaving adjacent their lower ends apertures receiving the cured to one ofthe trunnions and extending upwardly therefrom, and a connection betweenthe torque arm and said one bracket member at a point immediatelyadjacent the connection between said one bracket member and the transommember and substantially spaced from the connection between the torquearm and the related trunnion.

6. A railway car truck according to claim 5, wherein the connectionbetween the torque arm and said one bracket member comprises a pin andslot connection accommodating movement of the brake package -in avertical direction and operable to restrain rotational movement of thebrake package on its trunnions.

References Cited in the le of this patent UNITED STATES PATENTS1,794,348 Chase Feb. 24, 1931 2,343,342 Tack Mar. 7, 1944 2,355,120 TackAug. 8, 1944 2,357,619 Tack Sept. 5, 1944 2,377,190 Tack May 29, 19452,423,694 Eksergian et al. July 8, 1947 2,431,774 Schumacher Dec. 2,1947 2,655,226 Tack et al. Oct. 13, 1953

